Business Segments (Product Revenue) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue from External Customer [Line Items]
Treatment And Refining Charges Included In Copper Concentrates Revenues	$ (162)	$ (147)	$ (433)	$ (378)
Royalty Expense	(75)	(46)	(217)	(112)
Export Duties Expense	(52)	(21)	(153)	(62)
Revenue from Contract with Customer, Excluding Assessed Tax	5,026	4,173	15,223	11,065
Revenues	4,908	4,310	14,944	11,362
Copper In Concentrates [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,743	1,571	5,093	3,793
Copper Cathode [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,271	1,197	4,159	3,192
Refined Copper Products [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	561	604	1,899	1,818
Gold
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,073	495	2,814	1,334
Molybdenum [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	286	213	882	661
Other Products Or Services [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	381	307	1,179	819
Sales [Member] \| Not Designated as Hedging Instrument [Member]
Revenue from External Customer [Line Items]
Matured derivative financial instruments	$ (118)	$ 137	$ (279)	$ 297

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Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Amount of expense related to royalty payments under a contractual arrangement such as payment for mineral and drilling rights and use of technology or intellectual property.

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